Motorcycle Stability Control via Yaw Rate Feedback

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Solution Overview

Problem

Motorcycles become unstable at high speeds and low-friction conditions, particularly during cornering, due to oscillations like weave, which existing stability control systems risk exacerbating by automatically controlling brakes without rider intention.

Innovation Solution

A controller system using a high-fidelity motorcycle-dynamics model predicts yaw rates and applies front and rear brakes only when the actual yaw rate is less than the predicted rate, stabilizing the motorcycle by comparing physical states to simulated ones and intervening with brake and throttle adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If automated brake control is applied to stabilize motorcycles, then stability control is improved, but safety deteriorates due to risk of capsizing without rider intention

Engineering Contradiction:
Improvestability controlVSAvoidcapsizing risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system continuously monitors actual yaw rate and compares it with predicted yaw rate from the simulation model, using this feedback to determine when brake intervention is necessary. This feedback mechanism allows the system to distinguish between normal oscillations and dangerous weave conditions, applying brakes only when actually needed to prevent capsizing while avoiding unnecessary intervention that could upset the rider.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system pre-calculates the predicted yaw rate using a high-fidelity simulation model before actual oscillation occurs. By having the predicted value ready in advance, the system can immediately compare it with actual measurements and respond rapidly to stabilize the motorcycle during dangerous weave conditions, improving response time and effectiveness.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If brakes are applied during all oscillations, then stability is improved, but control precision deteriorates by applying brakes when not needed

Engineering Contradiction:
ImprovestabilityVSAvoidbrake application timing
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The system uses continuous feedback comparison between actual and predicted yaw rates to precisely determine when brake application is warranted. This feedback mechanism prevents premature or unnecessary brake application, ensuring brakes are only activated when actual oscillation exceeds predicted thresholds, thereby maintaining high control precision.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes the parameter comparison threshold dynamically by comparing actual yaw rate against predicted yaw rate from simulation. This parameter-based decision criterion allows precise differentiation between normal handling inputs and dangerous oscillations, improving the accuracy of brake application timing.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If complex simulation models are used to predict operating states, then stability control accuracy is improved, but device complexity increases

Engineering Contradiction:
Improveprediction accuracyVSAvoidcontroller complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system creates a virtual copy of the motorcycle dynamics through a high-fidelity simulation model that runs parallel to the physical system. This digital twin (copy) predicts operating states and yaw rates, allowing the controller to compare virtual predictions with actual measurements without adding complex physical sensors or actuators, thereby maintaining accuracy while managing complexity.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The system replaces complex mechanical stabilization mechanisms with a computational approach using simulation models and electronic control. Instead of adding complex mechanical linkages or passive stabilization devices, the invention uses software-based prediction and electronic brake control to achieve stability, reducing mechanical complexity while maintaining or improving control accuracy.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP3458345B1A system and method to stabilize motorcycles
Publication Date: 2022.07.13 MECHANICAL SIMULATION CORP
  • EP3458345B1 patent drawingFigure 1
  • EP3458345B1 patent drawingFigure 2
  • EP3458345B1 patent drawingFigure 3

AI summary

A system and method utilize a computer simulation model of a motorcycle to predict operating states for a stable motorcycle at a given speed and steer angle. The operating state of a physical motorcycle can be measured and compared to that of the model at every instant in time to determine if the operating state of the physical motorcycle differs from that of the simulation model in such a way as to indicate loss of stability. The difference is used to intervene in the operation of the motorcycle independent of driver actions by application of brakes, modulating the engine torque or applying torques to urge the steering system in a corrective direction. By comparing the physical response of the motorcycle to that of the computer model in an on-board controller these interventions can be applied at a time and intensity to stabilize the motorcycle and prevent a loss of control.